Due to the spread of digital cameras and the increase in capacity of recording media in recent years, users can now store a vast number of personal contents such as images and movies. In addition, due to the popularization of social networks that can be used for sharing personal contents among users, personal contents are often shared between a user and a friend of the user's, for example.
The popularization of such social networks has been making it difficult for users to appreciate a vast number of images that are shared among users every day. Therefore, a user could miss images that are personally important to the user. For this reason, there is a demand for image evaluation technology that allows users to efficiently browse shared images.
As a conventional method for image evaluation, there has been a method of evaluating images shared among users by calculating an evaluation value for each of the images according to the number of votes for each image (evaluation on each image) (See Patent Literature 1).